Thread: Bad thermocouple?

My 5 year old natural gas water heater is all of the sudden cycled off. It never happened before and has now done it three times in the last week. I'm going to replace the thermocouple but figured I'd post a picture here to see if anyone sees anything odd in the pilot or burner. Thanks for any input...

Most likely the thermocouple.

It sure looks like a bad thermocouple seeing that the end is burnt up. A Honeywell slim jim (universal) should take care of it. Of course with my luck after 29 years of service experience that wont be it!

While a bad TC is the most likely culprit, there are other factors to consider. For one, the vent needs to be inspected and tested. I'm finding a higher and higher frequency of pilot outages caused by CO2 spillage displacing the O2 snuffing out the pilot. Could lead to CO problems as well. Ideally, a pro would test the TC millivolt output open and closed circuit then perform a dropout test. He would also verify gas inlet and manifold pressures under full load. Then perform combustion analysis with a draft interference/ worst case depressurization test. If this is a FVIR, check the screens for lint build up.

As for those universal TCs, yes, they may work but I highly recommend you use only TCs listed for use with that appliance as you may change the pilot dropout rate and void the warranty and listing.
Bob

Bob is 100% correct on that, and the safe way is the best way to proceed.
what is the brand of wh? even a Bradford White warranty is only 6 years minimum and thats tank only.
1 year on etc no labor....
Mind you a thermocouple is $8 and the service call recomended would run you ? $65-150.
this is your house correct? just a drop out test would take a tech 30 minutes ....and only since it is your house...that tc should put out 18-24 mv with no load from coaxial end to ground if its good. the one in the picture is not good.
the typical gas valve requires 2-5mv to stay open. does this wh have a vent switch or lint screen? not likely on a 5yr old water heater...but?
natural gas or propane?

Thanks for the help guys... still no hot water. Thank god for RVs. The wife is at her sister's, I'm waiting for the tank in the 5th wheel to heat up.

Anyhow, the TC from Home Depot has standard threads and mine are left-handed which got me poking around on the net. It turns out the WH has a re-called TC (5-year old Whirlpool). It looks like they'll send me a free replacement but I need it much sooner than that. I'm hoping I can find it locally tomorrow.

To answer some questions posed.... it's natural gas, I have a CO detector in the closet (yes it has louvered doors) with no alarms. Yep, it's my house. It was shutting off occasionally last week. I should have known better than to tear into it on a Sunday afternoon while all the stores are closed. I must have broken it for good while screwing around with it as it won't even work at all now. The pilot won't stay lit for more than 5 seconds and I don't think it's safe anyhow.

Originally Posted by Jack Murdock

Bob is 100% correct on that, and the safe way is the best way to proceed.
what is the brand of wh? even a Bradford White warranty is only 6 years minimum and thats tank only.
1 year on etc no labor....

Bradford White's warranty is 6 years tanks and parts 1 year on the labor.

After calling Whirlpool's support center today (India, of course) I was sent to Lowe's for a replacement part. They gave me a whole new pilot, igniter and thermocouple assembly as part of the recall. I just put it together and all is well.

Quite a bit of run around but really a quick fix once I found and got the right parts.

Originally Posted by Matt Fellman

After calling Whirlpool's support center today (India, of course) I was sent to Lowe's for a replacement part. They gave me a whole new pilot, igniter and thermocouple assembly as part of the recall. I just put it together and all is well.

Quite a bit of run around but really a quick fix once I found and got the right parts.

Aww man a Whitlpool water heater. Man I am real sorry... wow... here is a thread you should read. Please do not let that part get your hopes up.

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